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/dev/urandom and /dev/random



Currently the permissions settings for these devices are uncertain.

MAKEDEV makes /dev/urandom mode 444 and /dev/random either mode 444 or more 
666.

For devfs I plan to make them both mode 644.  From reading the latest kernel 
source I see that writing to either of them gives the same result (so having 
different write permissions for them makes no sense).  The boot script 
/etc/init.d/urandom from the sysvinit package writes to /dev/urandom so root 
write access makes sense to me (sure root can write to it anyway but I think 
that the permissions should reflect the usage for clarity).

Also I suspect that if a malicious user ran "cat /dev/zero > /dev/random" 
then they could poison the random number pool so I think that mode 644 is the 
correct permissions for both devices.

Let me know if you disagree.  If there's no complaints then I'll file a bug 
against makedev to make it do the same.

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